Romano says he didn't shoot the suspect since he knew his gun was empty. The police revolver the suspect used holds 6 rounds. He fired two at Officer Martinez, then another three at Romano (based on the shots heard), meaning he still had one left. Even though the gun did not fire when he pulled the trigger when confronted the second time, only 5 shots were heard.
The murder charge being reduced to manslaughter would not have taken place as it was presented. The defendant alleged the officer beat him with his "billy club" in an alley, yet he suffered no injuries and was not in an alley when he killed the officer. Second, he said the gun "just went off" yet he fired at the officer twice. Third, forensics, even circa 1982, would prove the officer was on the ground when the shots were fired. Fourth, as Romano alluded to, the additional shots fired at him would further have discredited the defendant's justification. Finally, in a preliminary hearing, a court has no say on the degree of the charges filed, only if there is probable cause to take the case to a trial on the charge as filed. As such, the defendant's testimony would have little weight and the charge would not have been reduced, especially in such a high profile matter.